Synthetic computed tomography generation for abdominal adaptive radiotherapy using low-field magnetic resonance imaging

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Lessons from radiochemotherapy and modern image-guided adaptive brachytherapy followed by hysterectomy

International audiencePurpose: To analyze the clinical outcomes and the safety of radiochemotherapy (RCT) and image-guided adaptive brachytherapy (IGABT) and to evaluate the impact of hysterectomy (HT) as completion of treatment for cervical cancer.Methods and materials: 145 patients with locally advanced cervical cancer were treated at our institution. Patients underwent RCT and IGABT, then hysterectomy (HT) as completion of treatment was performed, with the exception of patients with surgical contraindications, para aortic metastatic disease or patients who refused surgery. Clinical outcomes and morbidity were retrospectively reviewed in both groups. Local relapse free survival (LRFS), pelvic relapse free survival (PRFS) and overall survival (OS) were analyzed.Results: Completion HT was performed in 90 (62.1%) patients. Complete histological response and microscopic disease were found in 77 patients (85.6%). Local relapse was observed in 14 patients (9.6%) without differences between completion HT group and the definitive RCT and IGABT group (Odds Ratio OR = 1.73 [0.57-5.23], p = 0.33). The estimated 3-year LRFS and PRFS for the entire population were respectively 90% [84%-94%] and 93% [87%-96%], with no significant differences between them (respectively Hazard Ratio HR = 0.57 [0.20-1.64], p = 0.30 and HR = 0.37 [0.10-1.31], p = 0.12). The estimated 3-year OS rate for the whole population was 84% [75%-91%] with no significant differences between groups (HR = 0.81 [0.32-2.06], p = 0.65). Regarding morbidity, grade ≥ 2 vaginal toxicity was more frequent in the definitive RCT and IGABT group (43.6% vs 26.7%, p = 0.04). All grade 4 toxicity events were reported in the completion HT group.Conclusions: Due to high severe toxicity, RCT and IGABT with dose escalation followed by completion hysterectomy don't seem compatible. No benefit and increased severe late morbidity were observed. Combined intracavitary/interstitial technique is mandatory in large target volume at brachytherapy

Multivariate normal tissue complication probability modeling of vaginal late toxicity after brachytherapy for cervical cancer

International audiencePURPOSE:To explore the best variables combination for a predictive model of vaginal toxicity in cervical cancer patients undergoing brachytherapy (BT).METHODS AND MATERIALS:Clinical and 3-dimensional dosimetric parameters were retrospectively extracted from an institutional database of consecutive patients undergoing intracavitary BT after external beam radiation therapy from 2006 to 2013 for a cervical cancer. A least absolute shrinkage and selection operator selection procedure in Cox's proportional hazards regression model was performed to select a set of relevant predictors for a multivariate normal tissue complication probability model of Grade ≥2 vaginal late toxicity. Outcomes reliability was internally assessed by bootstrap resampling method.RESULTS:One hundred sixty-nine women were included in the present study with a median followup time of 3.8 years (interquartile range [IQR], 1.9-5.6 years). The 2 years and 5 years cumulative incidence rates of Grade ≥2 late vaginal toxicity were 19.9% and 27.5%, respectively. Among 31 metrics and six clinical factors extracted, the optimal model included two dosimetric variables: V70Gy and D5% (the percentage volume that received a dose greater or equal to 70 Gy and the minimum dose given to the hottest 5% volume, respectively). Area under the ROC curve at 2 and 5 years of followup were 0.85 and 0.91, respectively. Regarding internal validation, median area under the ROC curve of bootstrap predictions was 0.83 (IQR, 0.78-0.88) and 0.89 (IQR, 0.85-0.93) at 2 and 5 years of followup, respectively.CONCLUSIONS:A multivariate normal tissue complication probability model for severe vaginal toxicity based on two dosimetric variables (V70Gy and D5%) provides reliable discrimination capability in a cohort of cervical cancer treated with external beam radiation therapy and BT

The impact of modern preoperative high-dose-rate brachytherapy in early-stage cervical cancer

International audiencePurpose: To analyze the clinical outcomes and the safety of preoperative high-dose-rate (HDR) image-guided adaptive brachytherapy (IGABT) followed by minimally invasive surgery (MIS) in the multidisciplinary management of early-stage cervical cancer.Methods and materials: Medical records of all consecutive patients with early-stage cervical cancer treated at our institution between 2012 and 2018 with preoperative IGABT in a multidisciplinary approach were reviewed. Treatment schedule was pelvic node dissection, preoperative IGABT followed 6-8 week later by MIS hysterectomy.Results: Seventy patients with cervical cancer FIGO stages (IB1 18.6%, IB2 75.7% and IIA1 5.7%) were treated by preoperative HDR brachytherapy. With a median follow-up of 37.4 months [95% confidence interval, 32.1-39.7 months] isolated vaginal vault recurrence was not observed, 3 pelvic relapses were reported (4.3%). None of patients received postoperative radiotherapy (EBRT) or radiochemotherapy. The estimated 3-year local and pelvis relapse free survival for the entire population were respectively 98% [95% confidence interval, 89%-100%] and 90% [80%-96%]. The estimated 3-year disease-free survival (DFS) for the entire population was 88% [77-94%]. The 3-year overall survival (OS) rate was 97% [88%-99%]. Microscopic vaginal resection margin (R1) was observed in one patient ([1].4%). Lymph-vascular space invasion (LVSI) was found found in 6 (8.6%) patients. Forty-eight late complications in 36 patients (51.4%) were observed. Five (7.1%) grade 3 vaginal wound dehiscence toxicities were observed. Urinary and gastrointestinal toxicities were grade 1-2. No grade 4-5 complications were observed.Conclusions: Preoperative image-guided adaptive brachytherapy followed by minimally invasive surgery allows high local control, reduces positive surgical margins and rates of lymph-vascular space invasion avoiding adjuvants treatments. Surgical approaches must be discussed with patients including preoperative brachytherapy as a down-staging treatment